三元乙丙橡胶混炼胶中炭黑引起的焦烧现象及其主要影响因素研究

三元乙丙橡胶(EPDM)混炼胶由于大量填充炭黑而引起的焦烧(简称炭黑焦烧)影响到混炼胶的存放、挤出和后续的制品成型加工。本工作从热力学和动力学角度探讨了EPDM混炼胶的炭黑焦烧的原因、过程和主要影响因素。试验结果表明,炭黑焦烧主要源于已分散的炭黑粒子在EPDM基体中的再次聚集和网络化。炭黑用量、分散水平以及混炼胶热处理对炭黑焦烧产生影响:炭黑用量达到某一临界值就会引发EPDM混炼胶出现炭黑焦烧现象,高温热处理的EPDM混炼胶更容易发生炭黑焦烧,而提高炭黑分散水平可以在一定程度上抑制炭黑焦烧。     

动态流变行为在三元乙丙橡胶/硅橡胶共混物形态结构研究中的应用

利用开放式炼胶机制备了三元乙丙橡胶(EPDM)与硅橡胶(SR)混炼胶和单相硫化硅橡胶(v-SR)的共混胶,通过流变行为研究了组成比例、界面交联作用等对共混体系形态结构的影响,并采用扫描电子显微镜和两相剥离强度对形态结构的研究结果进行了验证。结果表明,动态流变行为成功预测了高黏度聚合物复合体系的形态结构。共混物中EPDM的用量在30～70份（质量,下同）时,EPDM/SR混炼胶的形态呈双相连续结构。用超过1份的过氧化物交联剂对EPDM用量为70份的EPDM/SR混炼胶中的SR进行单相交联,v-SR的连续结构发生了融合,转变成颗粒状结构,且颗粒结构的相畴随着交联剂用量的增加而增大,而高剂量的交联剂可以使两相形成共交联。     

原位改性三元乙丙橡胶炭黑混炼胶与天然橡胶共混胶的性能

研究了三元乙丙橡胶(EPDM)炭黑混炼胶经偶联剂Si-69原位改性前后与天然橡胶(NR)共混胶的性能.结果表明,在EPDM炭黑混炼胶的原位改性过程中,Si-69在与炭黑表面作用的同时会与EPDM发生活性反应.这不仅增大了EPDM与炭黑间的亲和力,而且使EPDM的硫化反应活性增强,从而改善了共混硫化胶的物理机械性能.动态力学性能测试和扫描电子显微镜观察结果均表明,改性后的EPDM炭黑混炼胶与NR的硫化相客性增强.     

炭黑用量对过氧化物硫化三元乙丙橡胶性能的影响

以双叔丁基过氧化异丙基苯为硫化剂,通过无转子硫化仪、毛细管流变仪及橡胶加工分析仪考察了炭黑用量对乙烯含量不同的2种三元乙丙橡胶(EPDM)混炼胶硫化特性、流变行为、动态黏弹性能及硫化胶拉伸性能的影响。结果表明,随着炭黑用量的增加,2种EPDM混炼胶的焦烧时间(ts1)均缩短,正硫化时间均变化不大,门尼黏度均逐渐增大,混炼胶黏-切依赖性增大; 在相同炭黑用量下,乙烯含量高的混炼胶的ts1较短,硫化程度和硫化速率提高,2种EPDM混炼胶均表现出剪切变稀行为,乙烯含量高的EPDM混炼胶的剪切弹性模量明显高于乙烯含量低的EPDM混炼胶; 随着炭黑用量的增加,2种EPDM硫化胶的拉伸强度和100%定伸应力均不断提高,且高乙烯含量有助于提高EPDM硫化胶的拉伸性能。     

废轮胎热解炭黑在发泡三元乙丙橡胶中的应用

以废轮胎热解炭黑(CB_P)为增强填料,制备了发泡三元乙丙橡胶(EPDM),分析了CB_P的基本性能,研究了CB_P填充EPDM混炼胶的门尼黏度、硫化特性及发泡EPDM的物理机械性能、泡孔形态、压缩特性和能量吸收特性,并分别与牌号为N 660的炭黑、高岭土及碳酸钙填充EPDM进行了对比。结果表明,CB_P的主要成分是碳元素,灰分质量分数高达14.4%,粒径分布宽;在4种填料中,CB_P填充EPDM混炼胶的门尼黏度仅低于N 660填充EPDM混炼胶,焦烧时间和正硫化时间最短;CB_P填充发泡EPDM的拉伸强度和定伸应力优于高岭土和碳酸钙填充发泡EPDM,但发泡倍率小于后两者;CB_P填充发泡EPDM的泡孔大小均匀,泡孔直径为28μm,闭孔结构规则,孔壁光滑完整;在相同应变下,CB_P填充发泡EPDM的吸能能力与高岭土填充发泡EPDM相近。     

通过六官能团偶联剂和过氧化物改善PP／EPDM共混物的相容性

聚丙烯(PP)和乙烯-丙烯-二烯共聚物(EPDM)的共混物具有较高的商业价值，因为PP是一种价格低廉、易加工的热塑性材料。但因其常温下具结晶性而使得冲击强度很差。合成橡胶EPDM分散在PP基质中能提高PP的冲击强度，但同时降低了加工性能。提高PP／EPDM共混物冲击强度的条件包括：EPDM在PP基质中精细均一的分散；提高PP和EPDM相同的界面粘结；     

一种过氧化物硫化体系橡胶制件的制造设备及其制备方法

正授权公告号:CN 104072883B授权公告日:2016年5月4日专利权人:华南理工大学发明人:卢珣、龙娟本发明涉及一种基于三元乙丙橡胶(EPDM)的宽温域阻尼材料及其制备与应用。该阻尼材料的制备步骤为:在40~100℃下将EPDM和不同环氧化程度的环氧化天然橡胶(ENR)分别在开炼机上塑炼,并加入硫化剂、防老剂等混炼;然后取50~80份EPDM混炼胶和10~30份ENR混炼胶     

乙丙橡胶-苯乙烯-丙烯腈三元共聚物的制备方法

由北京工业大学申请的专利(公开号CN101735399A,公开日期2010-06-16)乙丙橡胶-苯乙烯-丙烯腈三元共聚物的制备方法,提供了一种EPDM-苯乙烯-丙烯腈三元共聚物的制备方法,即在EPDM的正己烷溶液中加入乳化剂(歧化松香)和氢氧化钾,乳化剂用量为EPDM的正己烷溶液质量的3.5%～4.5%,氢氧化钾用量为     

原位合成丙烯酸钠改性三元乙丙橡胶制备吸水膨胀橡胶

通过氢氧化钠(NaOH)和丙烯酸(AA)的中和反应,在三元乙丙橡胶(EPDM)中原位合成丙烯酸钠(NaAA),并在有机过氧化物的作用下将所得混炼胶进行硫化。比较了原位生成NaAA、直接添加NaAA和直接添加聚丙烯酸钠(PNaAA)等三种不同制备吸水膨胀橡胶方法对混炼胶硫化性能和硫化胶吸水膨胀性能的影响,主要研究了原位合成NaAA改性EPDM混炼胶的硫化特性和硫化胶的吸水膨胀性能及其力学性能。结果表明,原位合成NaAA改性EPDM的性能优于直接添加NaAA或PNaAA的EPDM,它不但具有良好的力学性能,而且还具有良好的吸水膨胀性能;随着NaAA含量的增大,硫化速度、硫化程度和吸水膨胀性能均有提高;吸水膨胀橡胶,在NaAA为30质量份时,力学性能具有最大值。过氧化二异丙苯(DCP)用量增大,吸水膨胀率下降,但仍可提高硫化胶的力学性能。     

超细改性硅酸盐材料在三元乙丙橡胶中的应用研究

文中介绍了超细改性硅酸盐材料(RF-1)在三元乙丙橡胶(EPDM)中的应用研究,通过比较添加不同用量RF-1的混炼胶、添加不同RF-1/炭黑的混炼胶以及偶联剂处理过的混炼胶的多种性能,研究RF-1对EPDM性能影响,得出结论。结果表明:RF-1可提高混炼胶的交联密度,混炼胶的拉伸强度、撕裂强度和硬度都是随RF-1用量的增大而变大;在热氧老化后,拉伸强度和撕裂强度下降且用量越大降幅越大,硬度则是随着RF-1用量的增加而提高。随着RF-1用量的增大,回弹率下降。RF-1的耐热氧老化性比炭黑好。经偶联剂处理后的混炼胶力学性能更好些。     

EPDM与维尼纶线骨架层粘合的研究

采用直接粘合法,研究了粘合剂RS/A的配比、白炭黑用量及其粒子大小、促进剂的选择、氧化锌用量及混炼工艺对EPDM与维尼纶线骨架层粘合的影响。结果表明:粘合剂RS/A的配比为4∶3时,EPDM与维尼纶线骨架层的粘合力最好;随着白炭黑用量的增加,粘合力提高;比表面积为150~215m2g-1时,粘合力较好;选择后效性促进剂有利于粘合;氧化锌用量增大至8~10份时,粘合力最好;采用二段混炼法有助于提高粘合力。以此确定的配方,生产的胶管,经装车运行5a,没有出现因粘合问题引起的起泡、分层、打皱等缺陷。     

提高PU胶粘剂粘接EPDM材料强度的研究

为了提高聚氨酯胶粘剂粘接三元乙丙非极性橡胶材料的粘接强度，在三元乙丙橡胶配方中添加石油树脂和聚丁烯作增粘剂。测试了新配方产品的力学性能和与聚氨酯胶粘剂的粘接强度。结果表明，聚丁烯和石油树脂都可以提高PU胶对EPDM的粘接性能，但是聚丁烯对EPDM的力学性能有一定的影响。当在每百份EPDM中添加15份石油树脂，可使之保持良好的力学性能，其与PU胶粘剂的粘接性能亦获得了改善。     

耐热EPDM汽车多楔带产品的研制

以三元乙丙橡胶（EPDM）为主胶品种,骨架材料选用EPDM浸胶处理的高模量低收缩聚酯线绳,表面织物选用涤棉布,在压缩层胶料配合中加入预处理短纤维,研制出一种新型耐热EPDM汽车多楔带产品。所研制的EPDM多楔带采用四轮疲劳试验机进行动态疲劳寿命测试,运行450h停止试验,检查皮带完好,未出现任何裂纹、掉楔、起球和断裂等失效现象,并且聚酯线绳界面粘合良好,完全满足现代汽车对传动带的要求。     

Effects of EPDM‐g‐MAH compatibilizer and internal mixer processing parameters on the properties of NR/EPDM blends: An analysis using response surface methodology

This study evaluates the effects of ethylene‐propylene‐diene‐monomer grafted maleic anhydride (EPDM‐g‐MAH) and internal mixer melt compounding processing parameters on the properties of natural rubber/ethylene‐propylene‐diene rubber (NR/EPDM) blends. Using Response Surface Methodology (RSM) of 2⁵ two‐level fractional factorial, we studied the effects of NR/EPDM ratio, mixing temperature, Banbury rotor speed, mixing period, and EPDM‐g‐MAH contents in NR/EPDM blends. The study found that the presence of EPDM‐g‐MAH in NR/EPDM blends had a predominant role as a compatibilizing agent, which affected the processability and properties of the final material. We also determined the model fitting with constant determination, R² of 99.60% for tensile strength (TS) response with a suggested combination of mixing process input parameters. The reproducibility of the proposed mixing strategy was then confirmed through model validation with a minor deviation at +2.303% and higher desirability of 0.960. This study is essential in providing a process design reference for NR/EPDM blends preparation by melt‐blending and the role of a compatibilizer from the systematic Design of Experiment (DOE) approach. The experimental findings were further supported with swelling and cross‐link density measurements, differential scanning calorimetry analysis, and observation of fracture morphology using a scanning electron microscope. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42199.     

Effect of processing parameters on the surface resistivity of ethylene propylene diene terpolymer/multiwalled carbon nanotube nanocomposites

In this study, ethylene propylene diene terpolymer (EPDM) is melt‐mixed with multiwalled carbon nanotube (MWCNT). To realize full‐scale application of MWCNT to the rubber industries, the effect of melt‐processing parameters on the surface resistivity in the rubber/MWCNT nanocomposites should be well understood. The effect of rotor speed, mixing temperature, and annealing time on the surface resistivity of the EPDM/MWCNT nanocomposites has been investigated. The surface resistivity of EPDM/MWCNT nanocomposites with 3 phr MWCNT increases with increasing the rotor speed and decreasing the mixing temperature. Tensile strength and tensile modulus of EPDM/MWCNT (3 phr) nanocomposites are higher than those of EPDM, respectively. For the nanocomposite with 3 phr MWCNT loadings, surface resistivity increases as the annealing time at room temperature increases. This is the first report that surface resistivity of rubber/MWCNT nanocomposites increases significantly on annealing at room temperature. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40129.     

Adhesive tack and green strength of EPDM rubber

Measurement of tack of EPDM (ethylene-propylenediene terpolymer) rubber with natural rubber (NR) of four different molecular weights, styrene-butadiene rubber (SBR), butadiene rubber (BR), bromobutyl rubber (BIIR), and polychloroprene rubber (CR) was done over a range of rates of testing, contact times, and temperatures of contact. The effect of different additives, namely carbon black, phenol-formaldehyde resin, coumarone-indene resin, and methyl methacrylate is also reported. Green strength of all the rubbers was measured. Tack strength increases with increase in contact time for all the rubbers. Adhesive tack between EPDM and low-molecular-weight NR is much higher than that between EPDM and NR of high molecular weight. Tack strength of EPDM with BIIR is the highest among the tack values obtained for synthetic rubbers. The adhesive tack between EPDM and natural/ synthetic rubber passes through a maximum when plotted against temperature of contact. It increases with testing rate. All these phenomena could be explained in terms of interdiffusion of rubber chains under different conditions and solubility parameter of two contacting rubbers. It was observed that tack strength varies with (contact time)^1/2 and (rate)^1/2 in accordance with the reptation theory. Phenol-formaldehyde resin (PF) or coumarone-indene (CI) resin in EPDM improves the tack strength quite significantly. The resin in the NR phase does not have a marked effect. The presence of carbon black decreases adhesive tack strength between EPDM and NR. The surface of EPDM, however, becomes smoother with the addition of the additives. Peel tests and commercial tack tests give similar results in the tack strength between EPDM/NR and EPDM/SBR.     

EPDM rubber reclaim from devulcanized EPDM

Two types of ethylene–propylene–diene monomer (EPDM) rubbers, namely an efficient vulcanized (EV) and a semiefficient vulcanized (SEV), have been used to produce devulcanizates in a continuous setup. The devulcanizates are re‐cured using the same recipes as for the virgin rubber. The influence of mixing it with virgin rubber compound, the addition of extra sulfur, the operating devulcanization conditions, and the excess of devulcanizing agent on the mechanical properties (hardness, tensile strength, and compression set) of the reclaim rubbers are studied. Most of the reclaims produced show slightly inferior mechanical properties compared to the virgin rubber. Surface imperfection was observed on the devulcanizate with high devulcanizing agent content. Excellent mechanical properties (all above the standards) of the reclaim were found when the devulcanized profile material was used (EV‐EPDM) to replace the virgin one for application as a roofing sheet material (SEV‐EPDM). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5948–5957, 2006     

硅橡胶/顺丁橡胶/乙丙橡胶共混材料的研究

针对硅橡胶具有较高耐热性．但力学性能差；三元乙丙橡胶（EPDM）力学性能较好，但互粘性较差；顺丁橡胶（BR）弹性好．但加工性能堇的特点，提出了将硅橡胶、三元乙丙橡胶与顺丁橡胶共混的方法，制成共混材料；再通过测定样品的性能，确定共混的最佳配比。结果表明：BR与EPDM、硅橡胶相客性较好，可达到共硫化；硅橡胶／BR／EPDM质量比为20／30／50时，共混物的物理机械性能和老化性能较好；用过氧化二异丙苯（DCP）／硫磺作硫化剂要好于用硫磺、过氧化二苯甲酰（BPO）和硫磺／BPO硫化剂。试样的耐热老化性能、邵尔A型硬度和扯断伸长率较好，其中样品的综合性能具备了硅橡胶、顺丁橡胶和三元乙丙橡胶的优点。     

Effects of interface reactions in compatibilised ground tyre rubber polypropylene elastomeric alloys

Abstract

Compounds of ground tyre rubber (GTR) and polypropylene (PP) were prepared in an internal mixer and characterised by means of mechanical, thermal and morphological testing. Only physical melt mixing could not provide a suitable interface compatibilisation and leads to compounds with poor mechanical properties. However, the application of a reactive melt mixing process, using organic peroxides as radical donators, was found to be suitable to initiate a compatibilisation reaction via interphase grafting. These compatibilised GTR/PP elastomeric alloy (EA) systems exhibit interesting mechanical properties which are close to that of conventional two phase thermoplastic elastomers (TPE) based on dynamically vulcanised ethylene propylene diene monomer (EPDM)/PP blends. Results of the morphology investigations substantiate the occurrence of a compatibilisation reaction between rubber particles and PP matrix during reactive mixing which is most probably responsible for the enhanced material properties of the GTR/PP EA.     

NR/EPDM 的共硫化

利用环氧化天然橡胶(ENR)与天然橡胶(NR)和三元乙丙橡胶(EPDM)均有很好相容性的特点，采用硫化促进剂预混工艺对NR／EPDM并用胶实施共硫化。考察了其对NR／EPDM并用胶的硫化特性、硫化胶的物理机械性能和耐热空气老化性能的影响。结果表明：本工艺确实能改善NR／EPDM的共硫化性能，所得硫化胶物理性能较好且操作简单。